医学显影剂四氧化三铁纳米颗粒制备及细胞毒性研究

Preparation and cytoprotic toxicity of Fe_3O_4 nanoparticles as the medical imaging agent

采用多聚醇法制备出水溶性的超小粒径(USPIO)的Fe_3O_4颗粒,并用羧基聚乙二醇(HOOC-PEG-COOH)和氨基聚乙二醇(HOOC-PEG-NH2)对其进行表面修饰.实验优化了Fe_3O_4纳米颗粒的制备方法,用透射电镜(TEM)观测Fe_3O_4纳米颗粒的晶体粒径.测定磷酸盐缓冲溶液(PBS,p H=7.4)中的稳定分散性.测定Fe_3O_4纳米颗粒和Fe_3O_4@PEG颗粒的r2/r1值.采用MTT法检测纳米颗粒在体外条件下对人肺癌H1299细胞生长的抑制作用,确定其细胞毒性的大小.实验结果显示:Fe_3O_4纳米颗粒,在生理条件下分散稳定且粒径小于5 nm,对H1299细胞的生长没有明显的影响.其粒径、形貌、分散稳定性和弛豫性能符合显影剂要求.

Magnetic Fe3O4 nanoparticles,with super paramagnetic properties used as contrast agent in magnetic resonance imaging（ MRI）,show unique function and other advantages,such as good biocompatibility and surface modification. Therefore,the application of magnetic nanoparticles in vivo shows great value in biomedicine. We prepared ultra small size of Fe3O4 nanoparticles by polyethylene glycol,and measure hydraulics size of particle in this experiment. DLS map displayed that Fe3O4 nanoparticles modified by PEG had better monodisperse stability. Experiments have proved that Fe3O4 nanoparticles modified,such as coupling copolymer on the surface or other high biocompatibility of polymer materials,change the specific surface area of nanoparticles,and have good dispersion stability. We detected Fe3O4 nanoparticles inhibitory effect to the growth of H1299 lung cancer cell in vitro by using MTT,and determined its cytotoxicity. Fe3O4 nanoparticles show great application values,which has become one of the most successful use of magnetic nanoparticles in biomedical applications.